Question

51. Tidal energy is renewable, ___________________and clean. (plenty)
52. Solar energy is_____________________, plentiful and clean. (renew)
53. I think that solar energy can be an_____________________ source of energy in the near future. (alter)
54. We should reduce the use of________________ at home. (electrical)
55. Scientists are looking for clean and ____________ sources of energy. (effect) 

Answer 1

51 plentiful

52 renewable

53 alternative

54 electricity

55 effective